Self-propelled colonoscope and cleaning process thereof

ABSTRACT

An endoscope is provided, being insertable in the colon of a patient, in a self-propelled manner, by driving a plurality of endless belts mounted along the outside surface of a flexible section of an insertion tube thereof, and having a cleaning mechanism therein to be easily cleaned after use. A self-propelled colonoscope ( 1 ) is an endoscope insertable in the colon by driving endless belts ( 10 ) mounted along the almost entire length of a flexible section ( 4 ) of an insertion tube ( 5 ), and having guide pipes, which guide returning endless belts, being mounted in the insertion tube thereof, each of said guide pipes being provided with an opening for a cleaning brush ( 35 ) and a casing ( 31 ), which surrounds the endless belt driving unit, being formed with a cleaning window ( 33 ), said window being provided with a lid ( 37 ).

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a self-propelled colonoscope,which does not cause pain to a patient during colono-endoscopicexamination for the colon, and a cleaning process for the colonoscope.More particularly, it relates to an improved endoscope, which isinsertable into the colon, in a self-propelling manner, by driving aplurality of endless belts mounted along the outside of a flexiblesection of an insertion tube thereof, and wherein a mechanism for easycleaning after use is provided, and it also relates to a cleaningprocess thereof.

[0002] Colonoscopes which can self-propel along with the shape of thecolon of a patient, without causing pain to the patient, have beenproposed. The inventor of the present invention disclosed in JapanesePatent Laid-open No.8-38416 an endoscope capable of self-propelling inthe colon of a patient by driving a plurality of endless belts mountedalong the outside of a flexible section of an insertion tube thereof.

[0003] The disclosed colonoscope is provided with a plurality of endlessbelts along the substantially entire length of the outside surface ofthe flexible section of the insertion tube. The endless belts are to bedriven by a driving mechanism mounted at the driving unit of thecolonoscope, and the outer circles of the endless belts touch the wallof the colon, so that friction between the colon wall and said endlessbelts will allow the distal end of the colonoscope to move spontaneouslyforward in the inside of the colon. The inner circle of each of theendless belts passes through one of guide pipes, provided in theflexible section of the insertion tube, and is led to the distal end ofthe flexible section of the insertion tube, and comes out to the outsidesurface of the insertion tube again, and the endless belts thereforerotate endlessly. With the endless belts contacting the colon wall, thecolonoscope can move spontaneously forward in the colon withoutexcessive extending or bending of the colon. The disclosed colonoscopeis smoothly insertable into the colon, keeping the position and shape ofthe colon relatively in the intact condition, so that little pain may becaused to the patient.

[0004] The disclosed colonoscope, however, has a lot of parts necessaryto be cleaned after use, such as endless belts, guide pipes, and driverollers, because these parts are exposed to patient's body fluid. Theendless belts, especially, will be adhered to by body fluid or excretionbecause of their direct contact with the colon wall. Further, the guidepipes, in which the endless belts pass, tend to be contaminated by thebelts. Still further, the drive rollers are in contact with the endlessbelts and may be consequently contaminated.

SUMMARY OF THE INVENTION

[0005] In view of above problems, it is an object of the presentinvention to provide a colonoscope which is insertable in the colon, ina self-propelling manner, by driving a plurality of endless beltsmounted at the outside surface of a flexible section of an insertiontube and has a mechanism therein to be easily washable after use, andalso to provide a cleaning process for the colonoscope.

[0006] According to a first aspect of the present invention, acolonoscope is insertable in the colon, in a self-propelling manner, bydriving an endless belt mounted at the outside surface of a flexiblesection of an insertion tube thereof. The colonoscope comprises a guidepipe, which forms a guide way for a returning endless belt in theflexible section of the insertion tube, said guide pipe having anopening, provided at least one end thereof, for insertion of a cleaningbrash.

[0007] While being washed, the guide pipe may be cleaned inside bytaking a cleaning brash in and out of the opening, after the endlessbelt is removed.

[0008] According to a second aspect of the present invention, acolonoscope is insertable in the colon, in a self-propelling manner, bydriving an endless belt mounted at the outside surface of a flexiblesection of an insertion tube thereof. The colonoscope comprises acleaning window at a casing surrounding a driving unit of theself-propelled colonoscope, said window having a lid for opening andclosing the casing.

[0009] The inside of the casing containing drive rollers therein can bewashed by immersing the colonoscope in a cleaning solution in a washingvessel, with keeping the lid open. During cleaning, an electricapparatus, such as a motor, may be placed above the surface of thecleaning solution.

[0010] In a cleaning process of the self-propelling colonoscopeaccording to the first aspect of the present invention, a colonoscope isinsertable in the colon, in a self-propelling manner, by driving anendless belt mounted at the outside surface of a flexible section of aninsertion tube thereof. The colonoscope comprises a guide pipe, whichforms a guide way for a returning endless belt in the flexible sectionof the insertion tube, said guide pipe having an opening, provided atleast one end thereof, for insertion of a cleaning brash. A cleaningbrash is inserted in said opening as to wash the inside of the guidepipe after the endless belt is removed.

[0011] Said guide pipe contaminated by the endless belt will be washedby taking a cleaning brash in and out of the guide pipe.

[0012] In a cleaning process for the self-propelling colonoscopeaccording to the second aspect of the present invention, a colonoscopeis insertable in the colon, in a self-propelling manner, by driving anendless belt mounted at the outside surface of a flexible section of aninsertion tube thereof. The colonoscope comprises a cleaning windowprovided at the casing surrounding the endless belt driving unit, saidwindow having a lid for opening and closing the casing. With said coverkept open, the colonoscope is to be immersed in the cleaning solution inthe washing vessel.

[0013] The cleaning solution is fed into the casing through the cleaningwindow. The drive roller or the inside of the guide pipe will beimmersed in the solution and washed. The cleaning window is usuallyclosed by the lid.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 shows a perspective view of the outer appearance of aself-propelled colonoscope according to one embodiment of the presentinvention.

[0015]FIG. 2 shows a side sectional view around the driving unit of theendoscope according to the embodiment.

[0016]FIG. 3 shows a sectional view of the flexible section of theinsertion tube of the endoscope according to the embodiment.

[0017]FIG. 4 shows a front view of the distal end of the insertion tubeof the endoscope according to the embodiment.

[0018]FIG. 5 shows a side view of a portion around the distal end of theflexible section of the insertion tube of the endoscope according to theembodiment.

[0019]FIG. 6 shows a view wherein the endoscope of the embodiment isbeing cleaned.

[0020]FIG. 7 shows a side sectional view of the driving unit of theendoscope according to another embodiment of the present invention.

[0021]FIG. 8 shows a view wherein the endoscope shown in FIG. 7 is beingcleaned.

DETAILED EMBODIMENTS OF THE INVENTION

[0022] Referring to the attached drawings, the detailed embodiments ofthe present invention will be set forth.

[0023]FIG. 1 shows a perspective view of the outer appearance of theself-propelled colonoscope according to one embodiment of the presentinvention.

[0024] A self-propelled colonoscope 1 is provided with an insertion tube5 comprising a distal section 2, a bending section 3, and a flexiblesection 4, a plurality of endless belts 10, an operation unit 11, and acasing 31 containing belt drive rollers therein.

[0025] The basic construction of the self-propelled colonoscope 1 is nowset forth as below.

[0026] The self-propelled colonoscope 1 comprises a belt driving section50 at its upper portion protected by the casing 31, and the operationunit 11 connected to the bottom of the casing 31, and further comprisesthe insertion tube 5, extending form the operation unit 11. Theinsertion tube 5 comprises the distal section 2, the bending section 3,and the flexible section 4. The bending section 3 can be flexed in alldirections by adjusting a control knob 19, mounted at the operation unit11.

[0027] The distal section 2 of the insertion tube 5 is provided, asshown in FIG. 4, with an image receiving window 6, two light projectingwindows 7, a suction and forceps opening 8, and an air-water nozzle 9.

[0028] The image-receiving window 6, equipped with an objective lens fora fiberscope, or an image pick-up device for an electronic scope, suchas a CCD, receives an image from the distal end of the tube. Thereceived image is transmitted to the operation unit 11 by an image guideof a fiberscope or lead wire of an electronic scope, which is insertedin the insertion tube 5, and then transferred to a display through anuniversal cord 21. A light guide such as an optical fiber, inserted inthe bore of each of the light projecting windows 7, runs through theoperation unit 11, via the universal cord 21, and is connected to alight source outside. The light source projects light from the distalend surface of the light guide.

[0029] The suction and forceps opening 8 is connected to a forcepsinsertion opening 17 at the operation unit so that a forceps 23 can beinserted in. The tip ends of the forceps 23, protruding from the distalend of the insertion tube 5, are manipulated by the proximal end of theforceps 23 as to treat a patient or collect a part of tissue of thepatient. The bore of the air-water nozzle 9 is a water-air supplychannel, and air or a cleaning solution is injected through theair-water nozzle 9 by manipulating the air-water supply button 13 of theoperation unit 11. Through the suction and forceps opening 8, body fluidor cleaning solution remaining in the colon is sucked out and excretedto the outside of patient's body. This operation is carried out by thesuction control valve 15 at the operation unit 11.

[0030] A plurality of endless belts 10 is mounted longitudinally on theoutside surface of the flexible section 4 of the insertion tube 5. Thediameter of the flexible section 4 is preferably 5 to 30 mm, and it isalso preferable that the number of the endless belt 10 is larger,because the larger the number of the endless belts is, the higher theself-propelling performance of the colonoscope becomes. As shown in FIG.3, the outside portion 10 a of the endless belt 10 is supported by aguide hook 43, formed on the outside surface of the tube 5. The insideportion 10 b of the endless belt passes through a guide pipe 41 in theinsertion tube 5. Each of the guide hooks 43, having a section whoseshape is an arc of larger than 180°, is longitudinally mounted at theflexible section 4 so that a portion of each of the endless beltsexposed from each of the guide hooks will be positioned radially andoutwardly; the outer circle of the endless belt 10 supported by theguide hook 43 is shown at the outside of the guide hook 43. When beinginserted into the colon, the endless belts can keep a sufficientcontacting area with the colon wall. Even when the flexible section 4 isseverely looped, the endless belts will not be off the guide hooks 43.

[0031] Each of the endless belts 10, the diameter of whose section is acircle of 1 to 3 mm or the width of whose section is a belt-like shapeof 1 to 3 mm, is made of a flexible and strong material such as, forinstance, carbon fiber or resin. It is preferable for the back side ofeach of the endless belts to be coated with a material having highfriction resistance as to rotate synchronously with the drive roller 51,shown in FIG. 2, or to have a rack formed.

[0032] During cleaning a colonoscope, each of the endless belts thereofneeds to be removed from the insertion tube, and it thus has a mechanismto be removed and reattached. The detail of the mechanism will bedescribed later.

[0033] Referring now to FIG. 2, the construction of the proximal part ofthe guide pipe 41 and the driving unit of the endless belt will be setforth.

[0034] The proximal section of the guide pipe 41 is connected to theguide pipe opening 35 formed in the side of the casing 31. The casing isbigger than the insertion tube 5 in diameter. The guide pipe 41 comprisea ramp (inclined section) 41 a, extending diagonally from the guide pipeopening 35 formed in the side of the casing 31 to the insertion tube 5.The guide pipe 41 also comprises a guide section 41 c, running throughfrom the ramp 41 a to the bending section 41 b and extending straight inthe insertion tube 5.

[0035] The drive roller 51, pinching the endless belt 10, is mounted onthe outside of the proximal end of the guide pipe 41 in the casing 31 ofthe driving unit. The endless belt 10 is penetrating the side wall ofthe guide pipe 41 at the ramp 41 a of the guide pipe 41. That is, theexterior portion 10 a of the endless belt 10, running into the guidesection 40 from the outside surface of the insertion tube 5 and thencrossing two holes formed at the side wall of the ramp 41 a of the guidepipe, extends toward the proximal end. The proximal portion of theendless belt 10 is wound and held by the drive roller 51. On the otherhand, the interior portion 10 b of the endless belt 10 runs at theinside of the guide pipe 41, penetrating the side wall of the guide pipe41 at the inside of the ramp 41 a of the guide pipe 41. The interiorportion 10 b of the endless belt 10 is led, via the pipe 41, to theguide hole 45, formed around the distal end of the flexible section 4 ofthe insertion tube 5. The guide hole 45, as shown in FIG. 5, ispositioned at 0 to 10 cm from the distal end of the flexible section 4.This is because the bigger the part where the inside wall of the colonis in contact with the outside portion 10 a of the endless belt 10 is,the higher the performance of self-propelling of the self-propelledcolonoscope becomes.

[0036] The drive roller 51 comprises a pulley 51 b, wound by the endlessbelt 10, and a bevel gear 51 a, connected to the same axis as is thepulley 51 b. The endless belt 10 and the pulley 51 b are engagedtogether by friction or a rack function. A bevel gear 53 being engagedwith the bevel gear 51 a is orthogonally arranged. A spur gear 57, whichis fixed to the proximal section of the gear axis 55 of the bevel gear,will be engaged with a large spur gear 59 fixed to the motor axis 61 ofa motor 63. Consequently, when the motor shaft 61 revolves by drivingthe motor 63, the bevel gear 51 a will revolve, via the large spur gear59, the spur gear 57, and the bevel 53, and accordingly the pulley 51 bwill revolve.

[0037] On the circumference of the large spur gear 59, the same numberof the drive rollers 51, the bevel gears 53, the gear shafts 55, and thespur gears 57 as the endless belts 10 are mounted in the sameconfiguration.

[0038] The motor 63, the large spur gear 59, the spur gear 57, the gearshaft 55, the bevel gear 53, and the drive roller 51 are mounted in thecasing 31 of the driving unit at the proximal end beyond the guide pipeopening 35. On the side of the casing 31 of the driving unit is formedwith a cleaning opening 33. Said opening 33 is provided with a lid 37,shown in FIG. 1, and can be open or closed.

[0039] The pulley 51 b is so rotated counterclockwise by driving themotor 63 that the endless belt 10 being engaged with the pulley 51 bwill rotate counterclockwise as well. At this time, if the outer circleof the endless belt 10 is in contact with the inside wall of the colon,the insertion tube will be fed forward the right direction of FIG. 2 byfriction between the endless belt 10 and the inside wall of the colon.The insertion tube 5 moves backward by rotating the motor 63 clockwise.

[0040] The guide section 40 is also provided at the outside 10 a of theendless belt, which is shown at the outside surface of the insertiontube 5, up to the flexible section 4 as to prevent the cleaning solutionfrom going in to the operation unit 11 during cleaning. In addition, thedriving unit 50 and the operation unit 11 are isolated each other by thewall 39 surrounding the guide pipe 41 and guide section 40, so that thecleaning solution will not get in the operation unit 11.

[0041] A cleaning process for the self-propelled colonoscope 1 accordingto the embodiment of the present invention will be described.

[0042]FIG. 6 is a drawing showing a condition such that the colonoscopeaccording to the present invention is being cleaned.

[0043] First, all the endless belts are cut and removed from theinsertion tube 5. Then, a cleaning brash is inserted in from the guidepipe opening 35, formed at the casing 31 of the driving unit, and takenin and out the inside of the guide pipe 41. Thus, body fluid or excretaadhered to the inside of the guide pipe 41 will be removed. By providinga detachable and attachable part on a certain portion of the endlessbelt, with using a magnet or a melting material at low temperatures, theendless belt may be reusable.

[0044] The insertion tube 5, the operation unit 11, and a lower portionof the driving unit casing 31 will be immersed in a washing vessel 91filled with a cleaning solution 93, with the lid 37 of the casing 31 ofthe driving unit kept open. At this time, by being observed from thecleaning opening 33, the colonoscope should be held in a manner suchthat the drive roller 51 in the casing of the driving unit, whichdirectly pinches the endless belt, is surely immersed in the cleaningsolution, and the motor 63 is placed above the solution surface. Asshown in FIG. 6, when the gear shaft 55 is immersed in the cleaningsolution 93, the solution will get in the driving unit 50 from thecleaning opening 33, then to the inside of the guide pipe 41 and guidesection 40 (referring to FIG. 2). The drive roller 51 is also immersedin the cleaning solution. That is, the surface area of the insertiontube 5, the inside and outside of the guide pipe 41, a portion from theguide pipe opening 35 to the distal end of the flexible section of theinsertion tube 5, the guide section 40, and the drive roller 51 are alltogether to be immersed in the cleaning solution 93. All thementioned-above portions are soaked 5 minutes in the cleaning solution93, which a proteolytic enzyme generally is used for, and then soaked 10minutes in a sterilizing solution for endoscopes, such as a Glutaralagent. The removed endless belts are also cleaned by soaking in thecleaning solution. A string 99 is hooked on a hook 95 formed at thecasing 31 of the driving unit, and using another stand 97 to hang thestring may reduce labor.

[0045]FIG. 7 shows a side sectional view of the driving unit of theself-propelled colonoscope according to another embodiment of thepresent invention.

[0046] In the driving unit of this embodiment, electric apparatuses suchas a motor and a group of gears necessary to be cleaned are sealed influid-tight condition.

[0047] A housing 65, having a bore 67 where a motor shaft 61 penetrates,is mounted in a portion between the motor 63 and a reduction gear 59 inthe casing 31 of the driving unit. The housing 65, made of plastics andthe like, whose outer circumference is fixed to the casing 31 of thedriving unit in a fluid-tight manner. The bore 67 of the housing 65 isso made a little bigger than the motor shaft in diameter that the motorshaft is freely rotatable. Two o-ring grooves are axially formed alongthe inner circumference at the center of the bore 67. Each of o-ringgrooves 69 is mounted with a rubber-made o-ring 71 surrounding the motorshaft 61. A portion between the two o-ring grooves is a little biggerdiametered hollow section 73. The hollow section 73, through thehydraulic port 75 charged with rubber, is connected to the outer surfaceof the casing of the driving unit toward the motor.

[0048] The hollow section 73 of the housing 65 is charged with hydraulicoil 77 by pressure of around one barometric pressure with a needlethrough the hydraulic port 75. The charged hydraulic oil 77 issurrounded by the two o-rings 71 and therefore sealed in the hollowsection 73. The passage in the hydraulic port of the needle will beclosed due to elasticity of the rubber after drawing the needle off.Since the oil has relatively high viscosity, a film is formed betweenthe o-rings 71 and motor 61, so that a seal against a cleaning solutionwill be provided. Consequently, when the colonoscope of the presentinvention, including the motor 63, is immersed in a cleaning solution,the solution will not get in the inside of the motor 63 because of theoil 77 around the motor shaft 61 having the pressure equivalent to thepressure of the cleaning solution.

[0049]FIG. 8 shows a condition such that the colonoscope is beingcleaned according to the embodiment of FIG. 7.

[0050] All the portions of the self-propelled colonoscope are immersedin the cleaning solution 93, placed lying down at the bottom of thewashing vessel, and the portion including the motor 63, as mentionedabove, is also immersed in the solution. Under this condition, the motor63 is isolated from the cleaning opening 33 by the hydraulic oil 77 inthe casing 65 surrounding the motor shaft 61, as shown in FIG. 7. Thepressure of the hydraulic oil 77 is the same as that of the cleaningsolution 93 so that the cleaning solution within the casing 31 of thedriving unit will not go into the casing of the motor containingelectric apparatuses.

[0051] Thus, cleaning of the self-propelled colonoscope can be easilycarried out by soaking the colonoscope in the washing vessel 91, withoutcare to oversee electric apparatuses, such as a motor, not to beimmersed in the solution.

[0052] In light of the above description, the present invention canprovide an endoscope which is insertable, in a self-propelled manner, inthe colon by driving endless belts mounted along the outside surface ofa flexible section of an insertion tube and which has a mechanism, inwhich the colonoscope can be easily cleaned after use, and a cleaningprocess thereof.

[0053] While the invention has been particularly shown and describedwith reference to preferred embodiment thereof, it will be understood bythose skilled in the art that various changes can be made thereinwithout departing from the spirit and scope of the invention.

What is claimed is:
 1. In a self-propelled colonoscope, insertable inthe colon of a patient, in a self-propelled manner, by driving anendless belt mounted along the outside surface of a flexible section ofan insertion tube thereof, the improvement comprising: a guide pipe,mounted in the insertion tube, which guides a returning endless belt;and an opening for insertion of a cleaning brush, being formed in oneend of the guide pipe.
 2. In a cleaning process for a self-propelledcolonoscope, wherein the colonoscope is insertable in the colon of apatient, in a self-propelled manner, by driving an endless belt mountedalong the outside surface of a flexible section of an insertion tubethereof, the colonoscope comprising a guide pipe, mounted in theinsertion tube, which guides a returning endless belt, and an openingfor insertion of a cleaning brush, being formed in the one end of theguide pipe; and wherein cleaning in the guide pipe of the endoscope iscarried out by inserting a cleaning brush in said opening after removingthe endless belt.